Raspberry Pi on Wheels: The $35 Computer in the Car

As our vehicles provide us with more and more data, this tiny, toylike computer could become a powerful tool for car geeks.

Cheap, small, and infinitely customizable: This is the recipe that brought gearheads flocking to the '32 Ford, '60s pony cars, and the imports of the 1990s and 2000s. Could the next object of their tinkering affection be not a car, but a tiny computer?

The Raspberry Pi costs $35, fits in an Altoid tin, and offers a blank slate for programmers. Hackers and hobbyists have found thousands of uses for the Pi, including some high-tech automotive applications. Here are some ideas to help you cook up some car-computing projects of your own.

In-Car Entertainment

While the Raspberry Pi's computing power has about as much muscle as a weak smartphone, its video and graphics capabilities rival the original Xbox. Techies immediately recognized the Pi's potential as a digital media hub. With some creative hacking, you can take this capability on the road.

A simple setup would be to use the Pi to play MP3s from a thumb drive. You can also add a video screen for in-car movies (passengers only, of course). Raspberry Pi tweakers have configured touchscreens from aftermarket backup camera kits as Pi interfaces, making it possible to have dashboard control of a Pi-powered car computer. You can even add a backup camera, to take the reverse-engineering full circle. Add-on GPS could bring Google Maps to your dashboard and let you track your car's movements when you're not at the wheel, something a dashboard GPS or smartphone could never accomplish.

OBD Reading

Modern on-board diagnostic systems monitor the inner workings of your engine. Tuning programs for laptops and smartphones can tap into this information, but keeping either of those devices tethered to your car full time would be a pain. With the right connections and communicating hardware, you can patch a Raspberry Pi into your car's diagnostic port to keep an eye on your running parameters at all times. Rig up a small LCD to show intake air temperature, throttle position, or instantaneous fuel consumption on the fly, or dive deeper into the coding and make a video display with virtual gauges for every parameter. Take it one step further and program the Pi to react to different engine readings: Set an on-screen warning to discourage high-RPM driving on a cold engine, or store fuel consumption data to help determine your most efficient cruising speed on highway trips.

Racer's Edge

Data logging has become a crucial part of racing, from Formula 1 down to the weekend amateur. A Pi-powered telemetry setup can store data from accelerometers and engine sensors to record lap speed and cornering force, with GPS data to track lap-by-lap improvements. Combined with video footage from an in-car camera, you can create a data-heavy replay of every race, including graphic displays for throttle and braking. To get started, aim for simplicity and monitor just a few data feeds, building in complexity as you go.

And Beyond

The fully customizable nature of the Pi means you can use it in just about any project where a laptop might be handy. And with its diminutive size and extremely wallet-friendly price, it can go places you'd never want to take a consumer computer.

However, Raspberry Pi projects don't come with instructions. The automotive environment poses dozens of challenges, starting with finding a power source with the right voltage that won't drain your battery (a power outlet that turns off with the car is ideal, though you'll have to protect the Pi from power spikes, and if you want a shutdown sequence you'll have to program it yourself). And any application, automotive or otherwise, is built from scratch.

But the Pi was born to teach programming to school kids, so even if you've never typed a line of code, you shouldn't be intimidated. While some of these projects replace existing technology, the beauty of the Pi is that you can design and tweak the system to do things no one else has tried, in the true DIY spirit.

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